For a machine-to-machine power supply system, a relatively high processing cost is often caused at a power supply terminal when abnormal power down occurs in a terminal device that consumes electric energy. Accordingly, many international standard organizations (e.g., National Institute of Standards and Technology, European Telecommunications Standards Institute, and Institute of Electrical and Electronics Engineers) all commit themselves to formulation of an abnormal power down reporting mechanism in order to definitely clarify the happening time and the subject of occurrence of the abnormal power down.
Further speaking, as compared to a normal shutdown reporting process which has a relatively sufficient processing time duration, an abnormal power down reporting process usually can only use electric power remaining in a capacitor of the terminal device to make a final report for abnormal power down when the power down occurs abruptly. As the electric power remaining in the capacitor of the terminal device is much limited, a time duration available for making the final report usually lasts for only 150˜250 milliseconds.
However, the abnormal power down reporting mechanism formulated currently is still too complex, so the reporting time duration of 150˜250 milliseconds may still be insufficient. Further, apart from considering the abnormal power down reporting of the single terminal device during formulation of the abnormal power down reporting mechanism, it is also necessary to consider the congestion problem which is easily caused when a large number of terminal devices make reports simultaneously. However, solving such a problem is also difficult for the abnormal power down reporting mechanism used currently.
Accordingly, in order to overcome the aforesaid shortcomings in the prior art, an urgent need exists in the art to more efficiently accomplish reporting of the abnormal power down of the terminal device in the machine-to-machine power supply system.